Sirius XM digital satellite radio
Discussion
If you've driven in USA you may have tried Sirius digital radio. It's useful to fill the big distances between local FM stations. Broadcast from satellite, reception is generally good although easily interrupted in parking garages or driving under trees as it's dependant upon "line of sight". (Their channel line-up includes BBC Radio 1 on a five hour broadcast delay. Weird.)
I've sometimes wondered if Sirius could be picked up in Europe or whether there's anything similar over here. Seems not. The closest thing is a company called Worldspace which plans to launch a European satellite radio service. The technology will be different. http://www.worldspace.com/maintenance/index.html
However, amongst the odd things you find on the internet it turns out the first Sirius satellites were the ones built for and used by the UKs failed satellite TV company British Satellite Broadcasting! (BSB's technology was the 'loser' when Sky and BSB combined to form BSkyB) So the UK ended up with larger satellite dishes than BSB's "Squarial" and our high powered satellites wandered off to make themselves useful transmitting radio to the small antennae on cars in USA.
Life just ain't fair!
"In July 1987 BSB selected Hughes Space and Communications Company to design and build two Hughes HS-376 satellites for the first television direct broadcast service (DBS) in the United Kingdom. A Delta-4925 rocket boosted the first BSB satellite, named Marcopolo 1, on August 27, 1989. Key to the BSB direct broadcast scheme was having a satellite with enough power to be received by very small (35cm/13.5 inch diameter), low-cost "Squarial" dishes, thereby making DBS both environmentally friendly and affordable for the public. The BSB satellite design represented the first high-power DBS use for the 376. Marcopolo 1 was acquired in-orbit by Nordiska Satellitaktiebolaget in 1993, and operated as Sirius 1. NSAB operated Marcopolo I (as Sirius 1) until sending it to junk orbit in 2003."
I've sometimes wondered if Sirius could be picked up in Europe or whether there's anything similar over here. Seems not. The closest thing is a company called Worldspace which plans to launch a European satellite radio service. The technology will be different. http://www.worldspace.com/maintenance/index.html
However, amongst the odd things you find on the internet it turns out the first Sirius satellites were the ones built for and used by the UKs failed satellite TV company British Satellite Broadcasting! (BSB's technology was the 'loser' when Sky and BSB combined to form BSkyB) So the UK ended up with larger satellite dishes than BSB's "Squarial" and our high powered satellites wandered off to make themselves useful transmitting radio to the small antennae on cars in USA.
Life just ain't fair!
"In July 1987 BSB selected Hughes Space and Communications Company to design and build two Hughes HS-376 satellites for the first television direct broadcast service (DBS) in the United Kingdom. A Delta-4925 rocket boosted the first BSB satellite, named Marcopolo 1, on August 27, 1989. Key to the BSB direct broadcast scheme was having a satellite with enough power to be received by very small (35cm/13.5 inch diameter), low-cost "Squarial" dishes, thereby making DBS both environmentally friendly and affordable for the public. The BSB satellite design represented the first high-power DBS use for the 376. Marcopolo 1 was acquired in-orbit by Nordiska Satellitaktiebolaget in 1993, and operated as Sirius 1. NSAB operated Marcopolo I (as Sirius 1) until sending it to junk orbit in 2003."
The CEO of Worldspace is a customer of mine and he tells me that they are actively talking to car manufacturers to offer the system for vehicles in Europe so maybe all is not lost.
The system was over here about 6/7 years ago and was free but as soon as the then current owners tried to charge for listening everyone dropped it like a stone. It then fell totally out of favour, the manufacturers (primarily Hitachi) stopped producing the receivers (which were portable with a built in mini dish pad at the back of the set). However I understand that this time around it will make an impact and hopefully will offer a better solution than the crappy DAB technology we have now.
The system was over here about 6/7 years ago and was free but as soon as the then current owners tried to charge for listening everyone dropped it like a stone. It then fell totally out of favour, the manufacturers (primarily Hitachi) stopped producing the receivers (which were portable with a built in mini dish pad at the back of the set). However I understand that this time around it will make an impact and hopefully will offer a better solution than the crappy DAB technology we have now.
Vauxhall was pushing DAB but that seems to have died a death. I have xm in the states as in free in GM cars fir six months and most have them on the rental cars. The funniest thing with the BSB squareal dish was somebody only a few years ago selling the dish and set top box at a boot sale and somebody was going to buy it!!
So is this Pure Highway, like the fabled Perth Pink, a DAB car radio for "laying down and avoiding?"
http://www.pureservicecentre.co.uk/acatalog/Car_Ra...
http://www.pureservicecentre.co.uk/acatalog/Car_Ra...
G4HKS said:
I understand that this time around it will make an impact and hopefully will offer a better solution than the crappy DAB technology we have now.
I've never managed to like the way DAB sounds. All of FM, Freeview and Sky seem to be at least as good for sound quality."The reason why the bit rates are higher on satellite than on DAB is that on satellite the bandwidth available is far higher in the satellite band in comparison with the VHF band which is where DAB presently transmits. There is nothing inherently wrong with DAB it just lacks enough bandwidth for the stations to properly exploit the system by using the higher bit rates."
Right. Found it.
Planet Rock is at 128 kbps on DAB compared to 160 kbps on Sky, enough to hear the difference.
Major BBC stations are at 128 kbps on DAB compared to 192 kbps on Sky and Freeview.
Game over! Just keep loading the Vette's CD-changer and put up with the Bose.
Edited by 5 USA on Tuesday 3rd February 23:37
5 USA said:
G4HKS said:
I understand that this time around it will make an impact and hopefully will offer a better solution than the crappy DAB technology we have now.
I've never managed to like the way DAB sounds. All of FM, Freeview and Sky seem to be at least as good for sound quality."The reason why the bit rates are higher on satellite than on DAB is that on satellite the bandwidth available is far higher in the satellite band in comparison with the VHF band which is where DAB presently transmits. There is nothing inherently wrong with DAB it just lacks enough bandwidth for the stations to properly exploit the system by using the higher bit rates."
Right. Found it.
Planet Rock is at 128 kbps on DAB compared to 160 kbps on Sky, enough to hear the difference.
Major BBC stations are at 128 kbps on DAB compared to 192 kbps on Sky and Freeview.
Game over! Just keep loading the Vette's CD-changer and put up with the Bose.
Edited by 5 USA on Tuesday 3rd February 23:37
The real issue is when all we're left with is low-quality DAB after the "digital switchover". In some environments it'll be fine (with the roof down, I'd struggle to hear the difference between 256kbps and 128kbps!) but in better environments with decent equipment it'll sound dreadful.
Maybe it's time for a Campaign for Sensible Use of Bandwidth (CAMSUB)?
Edited by GW65 on Wednesday 4th February 08:16
Actually you're all wrong on the limitation of DAB - yes the bit rate is lower but the actual problem was the adoption of an old compression algorithm that isn't as efficient as contemporary ones, not the problem of what chunk of the airwaves they could get.
SOme of the bandwidth 'on the air' limitations are down to the existence of lots of analogue traffic alongside digital. I believe one of the main interests for broadcasters going digital is that they can offer more channels over the already crowded airwaves.
DAB has a few weaknesses, 'muddy' sound quality, and it's either there or it isn't, unlike analogue which will continue in sound with more static when reception gets poor. Radio text on DAB is pretty good (like good continuous scrolling traffic info on some of the local stations, whcihc song you're litstening to etc.), but it's competing with internet radio too (which I'm a huge fan of).
We've got an FM/DAB/internet radio in the kitchen - mostly we're listening to, er, Heart radio from Woodstock, Ontario, after Sciencebird mistakenly tuned into looking for Heart in Cambs, oops! Better result though!
Gixer was less impressed when he jokingly asked for Radio Zimbabwe, he thought the songs were too long.
SOme of the bandwidth 'on the air' limitations are down to the existence of lots of analogue traffic alongside digital. I believe one of the main interests for broadcasters going digital is that they can offer more channels over the already crowded airwaves.
DAB has a few weaknesses, 'muddy' sound quality, and it's either there or it isn't, unlike analogue which will continue in sound with more static when reception gets poor. Radio text on DAB is pretty good (like good continuous scrolling traffic info on some of the local stations, whcihc song you're litstening to etc.), but it's competing with internet radio too (which I'm a huge fan of).
We've got an FM/DAB/internet radio in the kitchen - mostly we're listening to, er, Heart radio from Woodstock, Ontario, after Sciencebird mistakenly tuned into looking for Heart in Cambs, oops! Better result though!
Gixer was less impressed when he jokingly asked for Radio Zimbabwe, he thought the songs were too long.
It's a combination of low bit-rate and compression.
"At low bit-rates a layer 2 audio stream requires 100% more bit-rate than an MP3 stream giving the same audio quality. However the saving due to MP3 is negated by the overheads of packet and data group encoding (33%) and increased error protection required (between 33 and 100%). However with improving compression technology, transmission of low bit-rate specialist services is becoming more attractive."
"At low bit-rates a layer 2 audio stream requires 100% more bit-rate than an MP3 stream giving the same audio quality. However the saving due to MP3 is negated by the overheads of packet and data group encoding (33%) and increased error protection required (between 33 and 100%). However with improving compression technology, transmission of low bit-rate specialist services is becoming more attractive."
Thanks for the correction.
Next stab at getting DAB to address some of its current limitations is the DAB 2 standard (sorry I've I've got the name wrong) - some of the more modern DAB radios will be able to cope with a firmware update, so check if you're in the market for one that it will have this capability when it comes out - basically it'll be an up to date compression method to give better quality over the available bandwidth.
Will be interesting to see where DAB goes over the next few years - it seems quite limited to (mainly) the UK pursuing it. I think we want it - great to have some variety over the airwaves.
Next stab at getting DAB to address some of its current limitations is the DAB 2 standard (sorry I've I've got the name wrong) - some of the more modern DAB radios will be able to cope with a firmware update, so check if you're in the market for one that it will have this capability when it comes out - basically it'll be an up to date compression method to give better quality over the available bandwidth.
Will be interesting to see where DAB goes over the next few years - it seems quite limited to (mainly) the UK pursuing it. I think we want it - great to have some variety over the airwaves.
I never could get an XM or a Sirius signal in the UK 
(I brought portable units over in the past) as their satellites don't cover Europe.
It's a shame, it's an amazingly good service, especially while driving through the South where they have both kinds of music, Christian and Country.
(I brought portable units over in the past) as their satellites don't cover Europe.It's a shame, it's an amazingly good service, especially while driving through the South where they have both kinds of music, Christian and Country.
I've mentioned this before, but when I briefly tried the XM Radio in our rented Escalade last year, the sound was appalling like muffled AM and in glorious mono!
My brother has it in his Z06 and he's confirmed it is in mono too.
That's hardly a great step forward, is it?
My Denon home cinema amp has both internet radio and DAB and I use DAB because internet radio would drop out altogether occasionally and fail to reconnect. This could entirely be down to my wireless router though!
My brother has it in his Z06 and he's confirmed it is in mono too.
That's hardly a great step forward, is it?
My Denon home cinema amp has both internet radio and DAB and I use DAB because internet radio would drop out altogether occasionally and fail to reconnect. This could entirely be down to my wireless router though!
Seesm some of the itnernet radio tachnology can be flaky from time to time.
There's at least two 'chipsets' out there, and like lcd vs plasma, America vs Europe on sportscars there are pro's and con's of each (one technology is from Reciva, the otehr, I think begins with F). Added to this that there are so many different links/hops through any internet conenction (including the one from the telephone exhange to your house, telephone point to modem/router etc.) there's plenty of scope for problems.
I've found ours to be pretty reliable, only thing I had a little trouble with was a Zane Low listen again program (cwhich the radio can get) - normally live/listen again is good.
If you're getting dodgy internet service - try playing a track from a computer set up with a media serving programme (like media player 11) - then if that's a bit iffy suggests perhaps it is a wireless issue.
There's at least two 'chipsets' out there, and like lcd vs plasma, America vs Europe on sportscars there are pro's and con's of each (one technology is from Reciva, the otehr, I think begins with F). Added to this that there are so many different links/hops through any internet conenction (including the one from the telephone exhange to your house, telephone point to modem/router etc.) there's plenty of scope for problems.
I've found ours to be pretty reliable, only thing I had a little trouble with was a Zane Low listen again program (cwhich the radio can get) - normally live/listen again is good.
If you're getting dodgy internet service - try playing a track from a computer set up with a media serving programme (like media player 11) - then if that's a bit iffy suggests perhaps it is a wireless issue.
Godzilla said:
I've mentioned this before, but when I briefly tried the XM Radio in our rented Escalade last year, the sound was appalling like muffled AM and in glorious mono!
My brother has it in his Z06 and he's confirmed it is in mono too.
That's hardly a great step forward, is it?
My Denon home cinema amp has both internet radio and DAB and I use DAB because internet radio would drop out altogether occasionally and fail to reconnect. This could entirely be down to my wireless router though!
Wouldn't think that mono would make much difference in a C6, seeing that the clever people at bose made both rear speakers mono.My brother has it in his Z06 and he's confirmed it is in mono too.
That's hardly a great step forward, is it?
My Denon home cinema amp has both internet radio and DAB and I use DAB because internet radio would drop out altogether occasionally and fail to reconnect. This could entirely be down to my wireless router though!
I never used to listen to DAB in my XF as it always sounded flat, even with the Bowers&Wilkins speakers. Even my ipod was a significant improvement, and that irritates my if hooked up to the home hi-fi.
What denon amp have you got David? I'm thinking of replacing my faithful 3802...
JimexPL said:
What denon amp have you got David? I'm thinking of replacing my faithful 3802...
4803A. Fantastic! I used to buy the flagship A1 xxx models, but to be honest, this "2nd tier" model is so damned good I don't think I'd be able to tell the difference. It has almost all the features and power delivery of the latest A1 model, but not the expensive (and unnecessary) THX Ultra 2 certification.
I never used the THX processing on my A1 SR anyway.
Great HDMI amp.
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